On Tue, Mar 10, 2020 at 10:08:09AM -0700, Dmitry Torokhov wrote:
> Hi Linus,
>
> On Tue, Mar 10, 2020 at 03:28:18PM +0100, Linus Walleij wrote:
> > This adds a new driver for the Cypress CY8CTMA140 touchscreen.
> >
> > This driver is inspired by out-of-tree code for the Samsung
> > GT-S7710 mobile phone.
> >
> > I have tried to compare the structure and behaviour of this
> > touchscreen to the existing CYTTSP and CYTTSP4 generics and
> > it seems pretty different. It is also different in character
> > from the cy8ctmg110_ts.c. It appears to rather be vaguely
> > related to the Melfas MMS114 driver, yet distinctly
> > different.
> >
> > Cc: Ferruh Yigit <fery@xxxxxxxxxxx>
> > Cc: Henrik Rydberg <rydberg@xxxxxxxxxxx>
> > Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
> > ---
> > MAINTAINERS | 6 +
> > drivers/input/touchscreen/Kconfig | 13 +
> > drivers/input/touchscreen/Makefile | 1 +
> > drivers/input/touchscreen/cy8ctma140.c | 380 +++++++++++++++++++++++++
> > 4 files changed, 400 insertions(+)
> > create mode 100644 drivers/input/touchscreen/cy8ctma140.c
> >
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index 8e7433d74530..39163de1a082 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -4628,6 +4628,12 @@ T: git git://linuxtv.org/anttip/media_tree.git
> > S: Maintained
> > F: drivers/media/common/cypress_firmware*
> >
> > +CYPRESS CY8CTMA140 TOUCHSCREEN DRIVER
> > +M: Linus Walleij <linus.walleij@xxxxxxxxxx>
> > +L: linux-input@xxxxxxxxxxxxxxx
> > +S: Maintained
> > +F: drivers/input/touchscreen/cy8ctma140.c
> > +
> > CYTTSP TOUCHSCREEN DRIVER
> > M: Ferruh Yigit <fery@xxxxxxxxxxx>
> > L: linux-input@xxxxxxxxxxxxxxx
> > diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
> > index c071f7c407b6..279b96d1761a 100644
> > --- a/drivers/input/touchscreen/Kconfig
> > +++ b/drivers/input/touchscreen/Kconfig
> > @@ -214,6 +214,19 @@ config TOUCHSCREEN_CY8CTMG110
> > To compile this driver as a module, choose M here: the
> > module will be called cy8ctmg110_ts.
> >
> > +config TOUCHSCREEN_CY8CTMA140
> > + tristate "cy8ctma140 touchscreen"
> > + depends on I2C
> > + depends on GPIOLIB || COMPILE_TEST
> > + help
> > + Say Y here if you have a Cypress CY8CTMA140 capacitive
> > + touchscreen also just known as "TMA140"
> > +
> > + If unsure, say N.
> > +
> > + To compile this driver as a module, choose M here: the
> > + module will be called cy8ctma140.
> > +
> > config TOUCHSCREEN_CYTTSP_CORE
> > tristate "Cypress TTSP touchscreen"
> > help
> > diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
> > index 94c6162409b3..006444c8f87b 100644
> > --- a/drivers/input/touchscreen/Makefile
> > +++ b/drivers/input/touchscreen/Makefile
> > @@ -23,6 +23,7 @@ obj-$(CONFIG_TOUCHSCREEN_BU21029) += bu21029_ts.o
> > obj-$(CONFIG_TOUCHSCREEN_CHIPONE_ICN8318) += chipone_icn8318.o
> > obj-$(CONFIG_TOUCHSCREEN_CHIPONE_ICN8505) += chipone_icn8505.o
> > obj-$(CONFIG_TOUCHSCREEN_CY8CTMG110) += cy8ctmg110_ts.o
> > +obj-$(CONFIG_TOUCHSCREEN_CY8CTMA140) += cy8ctma140.o
> > obj-$(CONFIG_TOUCHSCREEN_CYTTSP_CORE) += cyttsp_core.o
> > obj-$(CONFIG_TOUCHSCREEN_CYTTSP_I2C) += cyttsp_i2c.o cyttsp_i2c_common.o
> > obj-$(CONFIG_TOUCHSCREEN_CYTTSP_SPI) += cyttsp_spi.o
> > diff --git a/drivers/input/touchscreen/cy8ctma140.c b/drivers/input/touchscreen/cy8ctma140.c
> > new file mode 100644
> > index 000000000000..fb79f4251122
> > --- /dev/null
> > +++ b/drivers/input/touchscreen/cy8ctma140.c
> > @@ -0,0 +1,380 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +/*
> > + * Driver for Cypress CY8CTMA140 (TMA140) touchscreen
> > + * (C) 2020 Linus Walleij <linus.walleij@xxxxxxxxxx>
> > + * (C) 2007 Cypress
> > + * (C) 2007 Google, Inc.
> > + *
> > + * Inspired by the tma140_skomer.c driver in the Samsung GT-S7710 code
> > + * drop. The GT-S7710 is codenamed "Skomer", the code also indicates
> > + * that the same touchscreen was used in a product called "Lucas".
> > + *
> > + * The code drop for GT-S7710 also contains a firmware downloader and
> > + * 15 (!) versions of the firmware drop from Cypress. But here we assume
> > + * the firmware got downloaded to the touchscreen flash successfully and
> > + * just use it to read the fingers. The shipped vendor driver does the
> > + * same.
> > + */
> > +
> > +#include <linux/module.h>
> > +#include <linux/kernel.h>
> > +#include <linux/input.h>
> > +#include <linux/input/touchscreen.h>
> > +#include <linux/input/mt.h>
> > +#include <linux/slab.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/io.h>
> > +#include <linux/i2c.h>
> > +#include <linux/gpio/consumer.h>
> > +#include <linux/regulator/consumer.h>
> > +#include <linux/delay.h>
> > +
> > +/* Used for driver name etc */
> > +#define CY8CTMA140_NAME "cy8ctma140"
> > +
> > +/*
> > + * The datasheet claims the device supports 4 fingers but the firmware
> > + * I've seen certainly only supports 2 fingers.
> > + */
> > +#define CY8CTMA140_MAX_FINGERS 2
> > +#define CY8CTMA140_GET_FINGERS 0x00
> > +#define CY8CTMA140_GET_FW_INFO 0x19
> > +
> > +struct cy8ctma140 {
> > + struct input_dev *input;
> > + struct touchscreen_properties props;
> > + struct device *dev;
> > + struct i2c_client *client;
> > + struct regulator *vcpin;
> > + struct regulator *vdd;
> > + struct gpio_desc *irq;
BTW, I do not think you are using this GPIO descriptor anywhere.
> > +};
> > +
> > +static irqreturn_t cy8ctma140_irq_thread(int irq, void *d)
> > +{
> > + struct cy8ctma140 *ts = d;
> > + u8 msgbuf0[1];
> > + u8 buf[31];
> > + struct i2c_msg msg[2] = {
>
> Drop explicit size?
>
> > + {
> > + .addr = ts->client->addr,
> > + .flags = 0,
> > + .len = 1,
> > + .buf = msgbuf0,
> > + }, {
> > + .addr = ts->client->addr,
> > + .flags = I2C_M_RD,
> > + .len = sizeof(buf),
> > + .buf = buf,
> > + },
> > + };
> > + u8 fingers;
> > + u16 f1x, f1y, f1z;
> > + u16 f2x, f2y, f2z;
> > + int ret;
> > + int slots[CY8CTMA140_MAX_FINGERS];
> > + struct input_mt_pos pos[CY8CTMA140_MAX_FINGERS];
> > +
> > + msgbuf0[0] = CY8CTMA140_GET_FINGERS;
> > + ret = __i2c_transfer(ts->client->adapter, msg, 2);
>
> ARRAY_SIZE() instead of 2 here and below.
>
> Who is taking the adapter lock so that __i2c_transfer() can be used?
> Why can't normal i2c_transfer() be used here?
>
>
> > + if (ret < 0) {
> > + dev_err(ts->dev, "error reading message\n");
> > + goto evt_out;
> > + }
> > + if (ret != 2) {
> > + dev_err(ts->dev, "wrong number of messages\n");
> > + goto evt_out;
> > + }
> > + if (buf[1] & 0x20) {
> > + dev_info(ts->dev, "invalid event\n");
> > + goto evt_out;
> > + }
> > +
> > + f1x = buf[3] << 8 | buf[4];
>
> get_unaligned_be16() here and below.
>
> > + f1y = buf[5] << 8 | buf[6];
> > + f1z = buf[7];
> > +
> > + f2x = buf[9] << 8 | buf[10];
> > + f2y = buf[11] << 8 | buf[12];
> > + f2z = buf[13];
> > +
> > + fingers = buf[2] & 0x0f;
> > + if (fingers == 0) {
> > + dev_info(ts->dev, "no fingers\n");
> > + goto evt_out;
> > + }
> > +
> > + input_mt_assign_slots(ts->input, slots, pos, fingers, 0);
> > +
> > + /*
> > + * When just handling two fingers this code is simple and we do not
> > + * need a loop increasing the complexity. If you need to modify
> > + * this driver for some firmware handling more than 2 fingers,
> > + * this is where you put in an array of coordinated and a loop
> > + * instead.
> > + */
> > + if (fingers >= 1) {
> > + dev_dbg(ts->dev, "%d fingers: finger 1 ID: %02x (%d, %d, %d)\n",
> > + fingers, buf[8] >> 4, f1x, f1y, f1z);
> > + input_mt_slot(ts->input, slots[0]);
> > + input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, true);
> > + input_report_abs(ts->input, ABS_MT_POSITION_X, f1x);
> > + input_report_abs(ts->input, ABS_MT_POSITION_Y, f1y);
> > + input_report_abs(ts->input, ABS_MT_PRESSURE, f1z);
> > + }
> > + if (fingers >= 2) {
> > + dev_dbg(ts->dev, "%d fingers: finger 2 ID %02x (%d, %d, %d)\n",
> > + fingers, buf[8] & 0x0f, f2x, f2y, f2z);
> > + input_mt_slot(ts->input, slots[1]);
> > + input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, true);
> > + input_report_abs(ts->input, ABS_MT_POSITION_X, f2x);
> > + input_report_abs(ts->input, ABS_MT_POSITION_Y, f2y);
> > + input_report_abs(ts->input, ABS_MT_PRESSURE, f2z);
>
>
> Please use touchscreen_set_mt_pos()/touchscreen_report_pos() so that we
> can support common transformation device properties from
> of_touchscreen.c
>
> > + }
> > + if (fingers > 2)
> > + dev_err(ts->dev, "%d fingers - unsupported!\n", fingers);
> > +
> > + input_mt_sync_frame(ts->input);
> > + input_sync(ts->input);
> > +
> > +evt_out:
> > + return IRQ_HANDLED;
> > +}
> > +
> > +static int cy8ctma140_init(struct cy8ctma140 *ts)
> > +{
> > + u8 addr[1];
> > + u8 buf[5];
> > + int ret;
> > +
> > + addr[0] = CY8CTMA140_GET_FW_INFO;
> > + ret = i2c_master_send(ts->client, addr, 1);
> > + if (ret < 0) {
> > + dev_err(ts->dev, "error sending FW info message\n");
> > + return ret;
> > + }
> > + ret = i2c_master_recv(ts->client, buf, 5);
> > + if (ret < 0) {
> > + dev_err(ts->dev, "error recieveing FW info message\n");
> > + return ret;
> > + }
> > + if (ret != 5) {
> > + dev_err(ts->dev, "got only %d bytes\n", ret);
> > + return -EIO;
> > + }
> > +
> > + dev_info(ts->dev, "vendor %c%c, HW ID %.2d, FW ver %.4d\n",
> > + buf[0], buf[1], buf[3], buf[4]);
> > + return 0;
> > +}
> > +
> > +static int cy8ctma140_power_up(struct cy8ctma140 *ts)
> > +{
> > + int ret;
> > +
> > + ret = regulator_enable(ts->vcpin);
> > + if (ret) {
> > + dev_err(ts->dev, "failed to enable VCPIN voltage\n");
> > + return ret;
> > + }
> > + ret = regulator_enable(ts->vdd);
> > + if (ret) {
> > + dev_err(ts->dev, "failed to enable VDD voltage\n");
> > + regulator_disable(ts->vcpin);
> > + return ret;
> > + }
>
> Use bulk regulator API?
>
> > +
> > + msleep(250);
> > +
> > + return 0;
> > +}
> > +
> > +static void cy8ctma140_power_down(struct cy8ctma140 *ts)
> > +{
> > + regulator_disable(ts->vdd);
> > + regulator_disable(ts->vcpin);
> > +}
> > +
> > +/* Called from the registered devm action */
> > +static void cy8ctma140_power_off_action(void *d)
> > +{
> > + struct cy8ctma140 *ts = d;
> > +
> > + cy8ctma140_power_down(ts);
> > +}
> > +
> > +static int cy8ctma140_probe(struct i2c_client *client,
> > + const struct i2c_device_id *id)
> > +{
> > + struct cy8ctma140 *ts;
> > + struct input_dev *input;
> > + struct device *dev = &client->dev;
> > + int ret;
> > +
> > + ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
> > + if (!ts)
> > + return -ENOMEM;
> > +
> > + input = devm_input_allocate_device(dev);
> > + if (!input)
> > + return -ENOMEM;
> > +
> > + ts->dev = dev;
> > + ts->client = client;
> > + ts->input = input;
> > +
> > + /*
> > + * This sets up event max/min capabilities and fuzz.
> > + * Some DT properties are compulsory so we do not need
> > + * to provide defaults for X/Y max or pressure max.
> > + *
> > + * We just initialize a very simple MT touchscreen here,
> > + * some devices use the capability of this touchscreen to
> > + * provide touchkeys, and in that case this needs to be
> > + * extended to handle touchkey input.
> > + *
> > + * The firmware takes care of finger tracking and dropping
> > + * invalid ranges.
> > + */
> > + touchscreen_parse_properties(input, true, &ts->props);
> > +
> > + ret = input_mt_init_slots(input, CY8CTMA140_MAX_FINGERS,
> > + INPUT_MT_DIRECT);
> > + if (ret)
> > + return ret;
>
> Since this holds and returns error codes, can we call this variable
> "error" please?
>
> > +
> > + input->name = CY8CTMA140_NAME;
> > + input->phys = "inpus/ts";
>
> Umm... If there is not a better physical location string, maybe just
> omit it?
>
> > + input->id.bustype = BUS_I2C;
> > + input_set_drvdata(input, ts);
> > +
> > + /* VCPIN is the analog voltage supply */
> > + ts->vcpin = devm_regulator_get(dev, "vcpin");
> > + if (IS_ERR(ts->vcpin)) {
> > + if (PTR_ERR(ts->vcpin) != -EPROBE_DEFER)
> > + dev_err(dev, "Failed to get VCPIN regulator %d\n",
> > + (int)PTR_ERR(ts->vcpin));
> > + return PTR_ERR(ts->vcpin);
> > + }
> > + /* According to datasheet this should be in the 2.7-3.6 V range */
> > + ret = regulator_set_voltage(ts->vcpin, 2700000, 3600000);
> > + if (ret) {
> > + dev_err(dev, "failed to set VCPIN voltage\n");
> > + return ret;
> > + }
>
> Shouldn't this already be in DT? We typically do not configure voltage
> on various rail unless in very specific circumstances.
>
> > +
> > + /*
> > + * VDD is the digital voltage supply
> > + * since the voltage range of VDD overlaps that of VCPIN,
> > + * many designs to just supply both with a single voltage
> > + * source of ~3.3 V.
> > + */
> > + ts->vdd = devm_regulator_get(dev, "vdd");
> > + if (IS_ERR(ts->vdd)) {
> > + if (PTR_ERR(ts->vdd) != -EPROBE_DEFER)
> > + dev_err(dev, "Failed to get VDD regulator %d\n",
> > + (int)PTR_ERR(ts->vdd));
> > + return PTR_ERR(ts->vdd);
> > + }
> > + /* According to datasheet this should be in the 1.71-3.6 V range */
> > + ret = regulator_set_voltage(ts->vdd, 2700000, 3600000);
> > + if (ret) {
> > + dev_err(dev, "failed to set VDD voltage\n");
> > + return ret;
> > + }
> > +
> > + ret = cy8ctma140_power_up(ts);
> > + if (ret)
> > + return ret;
> > + ret = devm_add_action_or_reset(dev, cy8ctma140_power_off_action, ts);
> > + if (ret) {
> > + dev_err(dev, "failed to install power off handler\n");
> > + return ret;
> > + }
> > +
> > + ret = devm_request_threaded_irq(dev, client->irq, NULL,
> > + cy8ctma140_irq_thread,
> > + IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
>
> The trigger (edge, level) should come from DT.
>
> > + CY8CTMA140_NAME, ts);
> > + if (ret) {
> > + dev_err(dev, "irq %d busy? error %d\n", client->irq, ret);
> > + goto err_reg_dis;
> > + }
> > +
> > + ret = cy8ctma140_init(ts);
> > + if (ret)
> > + return ret;
> > +
> > + ret = input_register_device(input);
> > + if (ret)
> > + goto err_reg_dis;
> > +
> > + i2c_set_clientdata(client, ts);
> > +
> > + device_init_wakeup(dev, 1);
>
> We should not mark device as wakeup source unconditionally. If there is
> "wakeup-source" property in DT, i2c core will do the right thing
> automatically. Please drop.
>
> > + return 0;
> > +
> > +err_reg_dis:
> > + cy8ctma140_power_down(ts);
> > + return ret;
> > +}
> > +
> > +static int __maybe_unused cy8ctma140_suspend(struct device *dev)
> > +{
> > + struct i2c_client *client = to_i2c_client(dev);
> > + struct cy8ctma140 *ts = i2c_get_clientdata(client);
> > +
> > + if (device_may_wakeup(&client->dev))
> > + enable_irq_wake(client->irq);
>
> No need as i2c core manages wake irq if there is "wakeup-source"
> property. So it should read:
>
> if (!device_may_wakeup(&client->dev))
> cy8ctma140_power_down(ts);
>
> > + else
> > + cy8ctma140_power_down(ts);
> > +
> > + return 0;
> > +}
> > +
> > +static int __maybe_unused cy8ctma140_resume(struct device *dev)
> > +{
> > + struct i2c_client *client = to_i2c_client(dev);
> > + struct cy8ctma140 *ts = i2c_get_clientdata(client);
> > + int ret;
> > +
> > + if (device_may_wakeup(&client->dev)) {
> > + disable_irq_wake(client->irq);
> > + } else {
> > + ret = cy8ctma140_power_up(ts);
> > + if (ret)
> > + return ret;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static SIMPLE_DEV_PM_OPS(cy8ctma140_pm, cy8ctma140_suspend, cy8ctma140_resume);
> > +
> > +static const struct i2c_device_id cy8ctma140_idtable[] = {
> > + { CY8CTMA140_NAME, 0 },
> > + { }
> > +};
> > +MODULE_DEVICE_TABLE(i2c, cy8ctma140_idtable);
> > +
> > +static const struct of_device_id cy8ctma140_of_match[] = {
> > + {
> > + .compatible = "cypress,cy8ctma140",
> > + },
> > +};
> > +MODULE_DEVICE_TABLE(of, cy8ctma140_of_match);
> > +
> > +static struct i2c_driver cy8ctma140_driver = {
> > + .driver = {
> > + .name = CY8CTMA140_NAME,
> > + .pm = &cy8ctma140_pm,
> > + .of_match_table = cy8ctma140_of_match,
> > + },
> > + .id_table = cy8ctma140_idtable,
> > + .probe = cy8ctma140_probe,
> > +};
> > +module_i2c_driver(cy8ctma140_driver);
> > +
> > +MODULE_AUTHOR("Linus Walleij <linus.walleij@xxxxxxxxxx>");
> > +MODULE_DESCRIPTION("CY8CTMA140 TouchScreen Driver");
> > +MODULE_LICENSE("GPL v2");
> > --
> > 2.21.1
> >
>
> Thanks.
>
> --
> Dmitry
--
Dmitry
